Multidimensional structural analyses of polymer materials through scanning transmission electron microscopy (STEM) are utilized to investigate diverse structural factors, encompassing three-dimensional spatial structure, elemental composition, chemical structure, and even time-dependent structural changes. STEM-EDX-tomography facilitates 3D elemental mapping of silica-filled rubber blends. STEM-EELS/ELNES phase mapping enables chemical mapping of the phase separation in polymer alloys. In-situ STEM provides the capability for real-time observation of the failure process of the adhesive interface, employing a tensile strain specimen holder.